


What Happens in the K Room Doesn't Stay in the K Room

by Aerstes



Category: Supergirl (TV 2015)
Genre: F/F, Lena and Kara don't know how to take turns topping tbh, One Shot, Smut, SuperCorp, but oh well I wrote it anyway, smut-ish tho i'm terrible with follow through, there's probably a hundred stories just like this one?
Language: English
Status: Completed
Published: 2017-07-30
Updated: 2017-07-30
Packaged: 2018-12-09 01:30:13
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,665
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11658789
Author URL: https://archiveofourown.org/users/Aerstes/pseuds/Aerstes
Summary: Lena discovers the Kryptonite room in the DEO, and can't help but want to have a little fun with it...





	What Happens in the K Room Doesn't Stay in the K Room

Things were a bit slow at the DEO lately. Slow, meaning that no one had recently attempted to destroy National City. Or the entire world. Or just Supergirl. Which, was still usually equally as stressful and destructive as when someone wanted to destroy National City, or the whole world.

And when things were slow, Kara got antsy. And when she got antsy, she liked to hit things.

So, naturally, Kara was logging a lot of hours training in the DEO lately. Not too many hours, though. Not enough to interfere with her quality time with Lena (the other thing she liked to do when she was antsy). She would normally clock out of CatCo, head over to the DEO, spend a few glorious hours punching things, and once Lena texted her letting her know that she was giving up on her work for the day, she would head over to either her place or Lena’s.

One day, however, after getting a little carried away with a sparring session, Lena was left wondering what her girlfriend was up to after she had left the office for the day, and decided that she would come surprise Kara by showing up at the DEO. She, of course, had made herself a DEO asset within weeks of beginning her relationship with Kara solely so that she be able to come see her at work. Especially considering that the alternative was standing outside the not-so-subtle government building, being side eyed by burly security guards, waiting for Kara to come outside.

Upon strolling into the DEO, Lena found Winn tapping away at his desk, and came up to ask him where Kara was.

“Oh, uh,” he said, spinning around in his chair, “I think she’s still sparring. She should be wrapping up soon, but I could go check on her and let her know you’re here.”

“No need,” Lena said, smiling, “Just point me in the right direction.”

After, admittedly, making a few wrong turns, Lena found herself going down a set of metal spiral stairs. At the bottom of the stairs was a large, empty room with gray walls and a few stray floor pads strewn about. In the middle of the room, James Olsen was working at a punching bag in quick, methodical movements. Next to him Kara was punching at the wrecked frame of a car.

An actual _car_.

And it went swinging with her every hit, nothing compared to the strength of Supergirl.

Lena’s mouth instantly went dry, and for a second she had to remind herself how to breathe properly.

Lena waited a moment before attempting to herself through an unceremonious series of mumbles and throat clearing. She realized that she was staring unapologetically at Kara, who was in only a sports bra and shorts, as she hit at the hunk of metal in front of her. Every time she threw a fist, her back and arm muscles flexed and tensed, preparing for the impact, her ponytail swinging back and forth. Sweat glistened off her forehead, her neck, the small of her back. She bounced back on the balls of her feet, hopping from one foot to another, dodging the idle swing of the car, constantly moving.

 _Seriously, Lena, breathe,_ she thought.

Lena cleared her throat again, finally making her presence known. James and Kara both stilled, looking to the stairwell. James gave a small nod of the head, acknowledging Lena, before grabbing a towel hanging on a stray chain next to him.

“Hey, babe,” Kara said, panting.

She grabbed a water bottle a few paces over from her, squirting water into her mouth, then on her face. Water dripped down her neck, splattering against her sports bra and her abs that flexed slightly with each labored breath she took. Kara let out a quick huff of breath, stray drips of water sputtering away from her lips. She swallowed another gulp of water, her neck tensing then relaxing again. Long, light eyelashes fluttered as she caught her breath.

Lena’s eyes were wide, any words she could have had caught helplessly in her throat.

“So,” Kara breathed, placing her hands on her hips, stray wisps of her hair slick with sweat, “what do you wanna do tonight?”

Lena bit her lip, closing the distance between the two of them in a few strides. She grasped at the soft cotton fabric of the leggings that sat just below the outline of Kara’s hip bones.

“You?” Lena whispered, pulling Kara in from her grip on the fabric.

Kara’s eyes widened in a second of surprise at Lena’s unexpected eagerness. Then she smirked, biting her bottom lip.

“Sounds good to me,” she said.

*

So, yes. Lena was a big fan of Kara working out. And it didn’t take long for a pattern to emerge, a pattern that everyone else at the DEO desperately tried not to notice.

Kara would show up after leaving CatCo for the day, change into workout gear, that seemed to grow smaller and more revealing with each passing day, and lose herself in a workout routine.

Lena would show up soon after, hover around the command center with Winn for a little while, as if she had shown up for some official business, only to conveniently notice that Kara was around, and meander to wherever she was.

Kara would suddenly preen in her work, her intensity doubling, the moment that Lena appeared to “just say hi”.

Lena would watch her girlfriend unabashedly for a little while, and soon after both girls would suddenly remember that there was something very important they had to do, and would be caught rushing out of the DEO together.

And that was the best case scenario.

Worst case scenario was that time Vasquez found them getting a little handsy in the hallway behind the weightlifting room.

And suddenly everyone at the DEO anxiously wondered when the next alien attack would be.

*

It was a Sunday. At approximately 10:23 AM, an alert sounded from the DEO, alerting all of its staff, on premise or not, of a Stage 3 threat. A massive, unclassified alien ship was entering the atmosphere, with weapons detected. Everyone came rushing into the DEO to spring into action.

The excitement turned to confusion, however, when no such ship could be found anywhere in the skies, or on any of the detection systems. Everyone stood at their posts, scratching their heads, when another alert came in, warning of weapon of catastrophic proportions being detected in the heart of National City. Both Supergirl and J’onn rushed towards it’s coordinates to see just what the hell it was, and discovered nothing. Except that they were near a dog park, much to Kara’s glee and J’onn’s dismay as he had to pull her away from a pair of Corgi’s so they could get back to work.

Shortly after they returned, even more confused than before, the “ _INTRUDER ALERT_ ” alarm started screeching all throughout the building, but absolutely no one had come or gone.

“Agent Schott, just what in the hell is going on here?” J’onn demanded impatiently.

“Uh…well…now don’t get mad. But I made some updates to the alert systems. And, well, somehow, it’s kind of sending out a bunch of false alarms.”

The screens of the command center all flashed red. _INCOMING METEOR, MASSIVE CASUALTIES PREDICTED_ , it warned.

“So how are we supposed to know which alerts are real and which aren’t?” Alex asked.

“I mean…we can’t really know,” Winn admitted. “So…we’re gonna have to double check every alert until I fix the system.”

“And how long will that take?” J’onn persisted, trying not to yell at Winn because he knew it would just make him stammer nervously.

“I don’t…uh…a few hours, at least? There’s a lot of code I’ll have to look through and check for problems. It might go faster if I call Lena in to help, she’s probably the only other person who would be able to pick out a problem in the code.”

 _CAUTION, SUN EXPLOSION IMMINENT,_ the screens warned.

The company of DEO agents around the command center groaned collectively.

“All right, call her in,” J’onn said, almost regrettably.

Meanwhile, Kara, who had been more than excited at the idea of something interesting finally happening in National City for the first time in a week in a half, let her disappointment out verbally through a long groan.

“Well, I guess I’m headed to the K room. Who wants to do some sparring?”

Behind her back, Alex, James, and a few DEO agents all brought their pointer fingers rapidly up to touch their noses. An agent named Tom, one of the athletic trainers, was the last to repeat this action. He sighed, and followed Kara to the training room lined with Kryptonite.

Lena arrived about half an hour later, looking very unlike the Lena Luthor everyone was used to seeing. She was wearing a T-shirt and sweatpants, her hair was tossed into a loose bun a top her head, and she wore hardly any makeup.

“What?” she snapped when Winn gave her a questioning look. “I sometimes wear clothes that aren’t dresses and heels. It is a Sunday, after all.”

It didn’t take Lena and Winn’s combined minds very long to guess where the issue in the code was. However, they would still have to run extensive tests to make sure that they were right, and that the problem had been fixed. Which required a lot of sitting and standing around, both on their parts and the parts of the staff that still needed to be on hand in case any of the stray alerts were, in fact, valid.

Lena was sitting cross-legged in her chair, eyes crossing as the screens in front of her flashed line upon line of computer code and processes. She had gotten so lost in computer geek mode the second that Winn had called her, that she forgot completely until that exact moment, that Kara was around somewhere, and that she hadn’t seen her.

“Where’s Kara?” Lena asked casually to Winn.

Winn, who knew that Kara was still sparring, poor Tom at the mercy of her limitless energy, even when she was slightly weakened by Kryptonite, tried not to groan outwardly.

“She’s…um, busy,” he said simply. He really needed Lena’s help, and knew that if she found out Kara was working out, she would disappear to watch her, like she was hypnotized or something.

“Busy with what?” Lena pressed, wondering why Winn was being withholding all of a sudden.

At the exact wrong moment, the doors of the K room, visible from where Lena and Winn were sitting at the command center, opened, an exhausted looking Tom tumbling out of it. Lena caught a glimpse of Kara inside, in a bright pink sports bra and tight, black compression shorts, and Winn knew that he had lost the battle for Lena’s attention.

“Uh,” Lena said, mind clearly elsewhere, “what’s in that room?”

Winn buried his head in his hands for a moment, cursing the day those two girls ever looked at one another.

“It’s a, um, a workout room that’s been lined with mild traces of Kryptonite. Kara uses it to be able to work on her fighting skills without relying on her superpowers.”

Lena’s eyes widened, pupils slightly dilated.

“So…Kara doesn’t have her strength in there?” she asked.

“Not all of it, no. Hey, Lena, could you look at…”

Lena was already gone.

“Goddammit,” Winn whispered angrily to himself.

*

Kara was wiping herself down with a towel, sort of bummed that Tom had ended their session so soon, when she heard the door open.

“Back for another round, Tom?” she asked, turning towards the door. “Oh, Lena! Hey! Did you and Winn figure out the problem with the computers?”

Lena shut the door behind her, smiling coyly.

“I think so,” she said, “but we won’t know for sure until we test everything out thoroughly. Which, is a whole lot of idle time, so I thought I would pop in and see what you were up to.”

Kara, who had been benefiting from Lena’s piqued interest in her work outs this past week, didn’t pretend not to know Lena’s true reason for “seeing what she was up to”. Kara was just surprised that Lena wasn’t exhausted yet from all the _interest_ she had been showing Kara lately.

Not that she was complaining, of course.

“Well I was sparring, but I think I broke Tom, so I was just about to come see how you and Winn were faring.”

“Broke him, huh?” Lena asked, stepping in towards the center of the circular room, closer to Kara. “I thought you had better control of you strength than that.”

“I don’t have much of any strength in here, actually,” Kara replied, clasping her hands behind her back, watching Lena’s movements closely, “There’s Kryptonite in the walls.”

“Doesn’t that make you sick?” Lena asked, looking Kara up and down for signs of weakness or fatigue.

Kara shrugged.

“I mean, I don’t like it all that much. But there’s not nearly enough in here to hurt me severely. It makes my stomach upset, and I get a little dizzy if I push myself too hard. But mostly it just dampens my powers.”

Kara moved to stand behind Lena, placing her hands comfortably on Lena’s hips, as she moved to whisper into her ear.

“But that doesn’t mean I can’t still wear someone out,” Kara said.

Lena smirked, turning so that she faced Kara, and moved to stand legs apart, knees bent, arms up in preparation to throw or receive a hit.

“Okay, show me what you’ve got, then.”

Kara crossed her arms, crinkling her nose in confusion.

“What?” she asked, taking a step back, creating some distance between Lena and herself. That wasn’t exactly what she meant…

“Come on,” Lena encouraged, stepping in, “I wanna see how I stand up against the Girl of Steel when you take the ‘steel’ away.”

Kara shook her head, placing her own hands carefully at her sides.

“Lena, I’m not gonna fight my girlfriend. That’s not cool.”

“It’s not fighting!” Lena insisted with a slight pout, “It’s training! Don’t you and your sister train together all the time?”

“Well, I mean, yeah,” Kara replied, “But…that’s different. Siblings can hit at each other every now and then and it’s not a big deal. This is different. Besides, Alex is an _agent_. She’s used to all of this.”

“But I’m a _Luthor_ ,” Lena rationalized, walking in a tight circle around Kara, eyes raking over her slowly. “You know how well trained I am in this kind of thing.”

Standing behind Kara, Lena moved Kara’s arms into a ready position as if she were her puppet, then moved again to stand in front of her.

“Lena…” Kara warned softly, large blue eyes looking up at her.

“You know I trust you,” Lena said calmly, “So, what is it? You’re afraid you might lose?”

Kara rolled her eyes.

“Lena,” she said flatly.

“Kara,” Lena replied instantly, mimicking Kara’s tone, smiling devilishly. “Or is it not what you’re afraid of? Hmm, what could it be, then? Maybe…”

Before Kara could comprehend what had happened, Lena had swiped her right leg underneath Kara’s feet, sending her toppling to the ground. Lena dropped down on top of her, throwing her weight to one side, and suddenly Kara found herself pinned to the foam mat beneath Lena, face down, her right arm pressed into her back, Lena hovering above her.

“Maybe you’re afraid that you might like it,” Lena whispered, her breath hot against Kara’s neck.

Kara would be lying if she said that she didn’t at that moment feel a rush of heat pool between her legs. Her lust grew even more so when, after squirming for a moment, she realized that she actually couldn’t free herself from beneath Lena’s strong grip. She had never experienced being completely overpowered by a lover, being someone who could literally lift several hundred tons at a time.

“Can you get up?” Lena asked, mouth hovering over Kara’s pulse point on her throat, close enough that her lips brushed against Kara’s skin.

“No,” she replied, a slight shiver shooting down her spine.

Lena hopped away from her hold on the girl beneath her, standing in the same ‘ready’ stance she had taken on before. Kara scrambled to her feet, suddenly more willing to play along with Lena’s little game.

“Come on, Supergirl,” Lena taunted playfully, “whatcha got?”

The next point was Kara’s, who used the inertia of throwing herself up and over Lena’s shoulder to drag Lena down with her. Lena pretended to be hurt long enough for Kara to release her grip, and she instantly flipped the two of them around to gain the upper hand. Unable to help herself, Lena bit at Kara’s neck, eliciting a yelp in response. A red mark formed where she had nipped at Kara. Lena pulled away.

“You can get hurt in here?” Lena asked, standing.

Kara nodded, pulling herself to her feet again.

“Yep. Just like anyone else.”

In the next moment, Kara had Lena pressed against the padded wall, arms pinned behind her back. Lena quickly freed herself enough to spin around, facing Kara. Eyes dark with lust, Kara pulled Lena into a heated kiss, quickly moving her mouth down to bite and suck and Lena’s neck. But Lena wasn’t done having her fun yet. She grasped Kara’s wrists and turned them around, placing Kara’s hands up above her head, pressing their bodies flush together and biting harshly at Kara’s bottom lip.

Testing the waters, Kara hopped up, wrapping her legs around Lena. Not wanting her girlfriend to drop to the ground with nothing to support her, Lena released her grip on Kara’s wrists to hold her up by gripping her ass. That’s all that Kara needed for her to push off of the wall and lock Lena’s legs between her own, causing Lena to topple to the ground. Kara cushioned her fall with her arms, and sat up, Lena now lying on the ground, Kara straddling her, their hips connected.

“That was cheating,” Lena said.

“No, that was strategy,” Kara replied, leaning down to bite at Lena’s earlobe.

 Lena moved her hands up Kara’s back and, questioningly, scratched her fingernails downwards. Kara gasped suddenly, clearly affected, and pressed her hips harder against Lena’s, causing both of the women to moan. Still, despite how much Lena was enjoying the view and the friction, she started this little tryst with one goal in mind, and she was determined to achieve it.

Kara wasn’t sure how, but in a moment Lena had overpowered her, flipping them around so that Kara was on her knees against the floor padding, her right hand holding herself up so her face didn’t press into the mat as well, and the left hand pinned behind her back. Lena was hovering over her, legs pressed on either side of Kara’s hips.

“Do you submit yet?” Lena asked, leaning over Kara to bite her shoulder.

“I could get out of this very easily, you know,” Kara replied, trying to hide the thrills she felt from the sting left by Lena’s nibbling.

“Oh I’m sure you could,” Lena purred, her free hand moving to pull at Kara’s shorts. “But do you really want to?”

Before Kara could decide, Lena had moved her hand into Kara’s shorts, teasing at her center.

Kara shivered, frozen, allowing herself to be wrapped up in the feeling of Lena’s touch.

But then she remembered herself. And Kara Danvers wouldn’t submit that easily.

She took the hand Lena was pinning her with, using it as leverage to pull herself away and then use the inertia she had created to half roll, half toss Lena to the other side of the mat. If Lena had wanted to, she could have instantly popped up and regained a fighting stance, but she seemed to be enjoying herself too much to resist letting Kara climb on top of her, their hips once more connected, Kara biting her lip as she drank in the sight of the girl beneath her: her messy hair, comfortable clothing (that she never thought Lena would be caught dead in outside her apartment before today), her tempting little smirk…

“Nuh uh,” Lena said, “You cannot look at me like that when I am trying to win a fight, here.”

Kara lifted up Lena’s shirt, pressing her lips against Lena’s stomach by her navel, leaving a torturously slow progression of kisses south. Lena let out a whimper.

“It doesn’t look like you’re trying all that hard to win,” Kara said, looking up at Lena, who was watching her every move intently.

“Well the first move I have in mind might make me accidentally knee you in the face, and that doesn’t seem like a good way to treat someone in the position you’re currently in.”

Kara smirked, and pulled herself off of Lena, much to her disappointment.

“Alright,” Kara said, standing again. “Even score, right?”

“No, I’m up by one,” Lena insisted, standing as well.

“Oh are you?” Kara said, faking out a handful of moves so that Lena kept ducking and stepping backwards, until she was close to the wall again.

Kara closed the gap between them, the two of them crashing against the padded wall as she captured Lena’s mouth with her own. Her hands roamed up into Lena’s shirt, savoring the familiar feeling of her skin. Lena let out a small groan, biting down on Kara’s shoulder.

“You are just all about the biting today,” Kara murmured, moving to pull Lena’s shirt up over her head so that she could replace the progression of her hands with her mouth.

“I like that I can leave a mark for once,” Lena said, “Oh, fuck.”

Lena’s nails dug into Kara’s back as she flicked her tongue over Lena’s nipple, her free hand pulling Lena’s sweatpants down in a swift movement and pressing a finger into Lena’s wet, eager center.

Lena bit down again, harder, eliciting a yelp from Kara, but she continued to set a painfully slow pace.

“Oh, I’m gonna need more than that from you, Kara,” Lena said into Kara’s ear.

Kara lifted her face, watching Lena’s reaction as she pressed another digit into her. Lena’s eyes fluttered shut, head pressing against the padding behind her, mouth parted. 

“What’s the score now?” Kara asked as she moved her hand progressively faster, Lena’s hips bucking in response.

“I don’t fucking care what the score is,” Lena gasped, “Just don’t stop.”

*

James, Alex, and Maggie entered the DEO. They had all gone out to check out whether or not there actually was a two hundred ton sea monster in the bay, as the alert system had indicated. No one was surprised to discover that there was nothing there, except a Sea Bass fish a fisherman was more than happy to show off to them. The trio rounded the corner to the DEO command center, seeing Winn working at his computer.

“Hey, man,” James said, “No sea monster.”

“Damn,” Winn said absently as he clacked away at his keyboard, “That would have been so cool.”

A dull thudding was heard from the direction of the K Room.

“Where’s J’onn?” Alex asked.

“Umm,” Winn said uneasily, “He suddenly felt compelled to get as far away from this floor of the building as possible.”

“Why?” Maggie asked.

“Well, you know, so he didn’t have to hear Lena’s thoughts anymore.”

Another thudding from the right, followed by a muted moaning sound.

“What the…” James began, when his eyes suddenly widened, realizing what was going on.

“What’s wrong with Lena’s thoughts?” Alex asked, oblivious. “I thought she was working on fixing the program?”

“She was,” Winn replied, still clacking away, “until she discovered the K Room.”

Another thudding sound, followed by a “fuck” and an “Oh God” coming from a female’s voice.

Maggie suddenly had to turn away from Alex, a laugh erupting out of her.

“What’s she doing in the K Room?” Alex asked, still a little slow on the uptake.

Another laugh came from Maggie, who was now doubling over, unable to contain herself. Almost at the same time, giggling could be heard within the K Room, followed by a grunt, and a more familiar voice yelling out “More, Miss Luthor!”

Alex’s faced turned a shade of scarlet never before seen on her before.

“Oh my God, why,” Alex whispered, burying her head in her hands.

Maggie’s laughter continued, only stopped briefly so that she could catch her breath.

“This is not funny, Maggie!” Alex hissed, smacking her girlfriend lightly on the arm. “My little sister is getting violated in there!”

More giggling, followed by a sharp, high pitched gasp, from within the K Room.

 “I dunno, Danvers. Kinda sounds like she’s okay with it.”

“If you stick around long enough, you’ll probably hear her violate Lena right back, again, if that makes you feel any better,” Winn said dryly.

Alex practically growled at Winn.

“Oh, Rao, please, Lena!” came Kara’s voice from the K room, followed by a string words that were most likely Kryptonian.

“You guys suck,” Alex said, turning to leave them. “And now I need to talk J’onn into mind wiping me before the mental scarring sets in.”

Maggie moved to follow Alex.

“I better go with her,” she said. “Good luck, Schott.”

Maggie went trotting down towards the stairwell that Alex had disappeared into.

James stood, tapping his fingers rapidly against the console of the command center.

Now it was Lena who had begun gasping and swearing.

“So,” James said, practically yelling to drown out the sounds of the two women in the K Room. “How are things going with the computers?”

“Good!” Winn yelled back, “I should have everything figured out, I just have to run some more tests!”

Thudding, and a long string of expletives from the right.

“Yeah, I’m out,” James said, and went to find somewhere to escape the noise.

“No, James, I have to stay here with the computers!” Winn pleaded, “Don’t leave me!”

James was already gone.

Winn groaned to himself, at the same time groaning came from the K Room.

“Oh would you two shut up?” Winn hollered, though they probably were too occupied to hear him.

*

Some time later, the two girls emerged from the K Room, both panting, shining with sweat, and tugging their quickly re-adorned clothing back into place.

Lena casually strolled over to the command center, a grin on her face that she couldn’t fight off. She cleared her throat, plopping back into the chair she had been sitting in earlier as if no time had passed since she had stepped away from it before. Kara moved to stand behind Lena’s chair, leaning against it lazily.

“How’s it going over here?” Lena asked, struggling to talk normally as she fought to regain her breath.

Winn rolled his eyes.

“It is going as well as it can when one half of the team working to fix the problem disappears to bang her girlfriend.”

Kara snapped to stand straight, eyes widening. Lena seemed unaffected by Winn’s statement, a self-satisfied grin still on her face.

“What did you say?” Kara asked, voice cracking.

“You heard me, woman. Oh, and Pam wants to see you in her office ASAP.”

Kara sighed heavily.

“Pam always ruins my fun,” Kara grumbled, and turned to head towards the HR office. As she turned, red scratch marks could be seen poking out from her tank top. Outside of the K Room, they were already healing, but Winn, of course, still had the bad luck of seeing them as Kara walked away.

Lena, still, grinned. Winn glared pointedly at her.

“I’m not even sorry,” Lena said smugly, and returned to her work.

“Yeah…” Winn mumbled to himself, “A mind wipe sounds pretty good right about now.”

**Author's Note:**

> I've had this file sitting around in my computer gathering dust for awhile, so I thought that I may as well post this anyway if for no other reason than to hopefully cheer someone up, ya know?  
> Hope you enjoyed it! I'm gonna (pretend) to keep working on another slowburn supercorp story I have in the works.  
> Come bug me on tumblr @ schatzietess.  
> Kudos and comments are always immensely appreciated! <3


End file.
